Needs to view and listen to terrestrial digital broadcasting always anywhere are growing with the spread of terrestrial digital broadcasting. For example, the needs are expanded dramatically by having carried the viewing function of the partial reception layer (one-segment broadcasting) of terrestrial digital broadcasting (ISDB-T System) adopted in the countries including Japan in the mobile telephone. Under such a situation, it is proposed that only the one-segment of terrestrial digital broadcasting is extracted and it is reradiated in an underground shopping area or a building where terrestrial digital broadcasting can not be received (see JP2005-341195A). A system which receives terrestrial digital broadcasting during running and reradiates it in cars in a rail train is also proposed (see JP2002-111609A).
However, when reradiating terrestrial digital broadcasting within the mobiles such as a rail train etc., broadcast wave is screened by a building etc. with movement of the mobile, and a reception status gets worse intermittently. Therefore, there is a problem that reception is un-continuable.